linux/drivers/net/wireless/ath/wcn36xx
Gustavo A. R. Silva ec431188b4 wcn36xx: Replace zero-length array with flexible-array
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200507151758.GA4962@embeddedor
2020-05-13 19:03:06 +03:00
..
debug.c wireless: Use octal not symbolic permissions 2018-03-27 11:01:13 +03:00
debug.h
dxe.c cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
dxe.h wcn36xx: Remove useless skb spinlock 2018-04-10 17:39:50 +03:00
hal.h wcn36xx: Replace zero-length array with flexible-array 2020-05-13 19:03:06 +03:00
Kconfig ath: fix SPDX tags 2019-06-26 18:11:06 +03:00
main.c wcn36xx: Fix error handling path in 'wcn36xx_probe()' 2020-05-11 15:37:21 +03:00
Makefile ath: fix SPDX tags 2019-06-26 18:11:06 +03:00
pmc.c wcn36xx: Fix dynamic power saving 2018-01-04 18:41:48 +02:00
pmc.h
smd.c wcn36xx: fix spelling mistake "to" -> "too" 2020-01-26 16:40:19 +02:00
smd.h wcn36xx: Add support for Factory Test Mode (FTM) 2018-05-25 13:17:28 +03:00
testmode_i.h wcn36xx: Add support for Factory Test Mode (FTM) 2018-05-25 13:17:28 +03:00
testmode.c netlink: make validation more configurable for future strictness 2019-04-27 17:07:21 -04:00
testmode.h wcn36xx: Replace zero-length array with flexible-array 2020-05-13 19:03:06 +03:00
txrx.c wcn36xx: don't keep reference to skb if transmission failed 2018-04-10 17:34:14 +03:00
txrx.h
wcn36xx.h wcn36xx: Track associated stations 2018-06-29 14:59:07 +03:00